Pneumatic motor.



T. P. snowm. PNEUMATIC MOTOR.

APPLICATION FILED NOV. 20, I914,

Patented Sept. 19, 1916.

UNITED STATES PATENT OFFICE.

THEODORE 1?. BROWN, OF \FJORCESJJER, MASSACHUSETTS, ASSIGNOR TO SIMPLEX PLAYER ACTION COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PNEUMATIC MOTOR.

Specification of Letters Patent.

Patented Sept. 19, 1916.

T 0 all whom it may concern Be it known that I, THEODORE P. BROWN, a citizen of the United States, residing at iVorcester, in the county of \Vorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Pneumatic Motors, of which the following, together with the accompanying drawings, is a specification.

The present invention relates to pneumatic motors for automatic musical instruments and has particular reference to that type of motor which is employed to move a perforated note sheet over the tracker bar of a piano player.

My invention contemplates the assemblage of a plurality of motor bellows, each having an individual controlling valve mechanism, and all connected for operation by a single crank shaft.

The invention resides in simplifying the construction of a motor of this type, and in rendering the same more eflicient, in operation, than those heretofore constructed. Further advantages gained therefrom are to be found in a reduction in the number of parts, and in an improved construction which readily adapts itself to theseparation, and assembly, of the individual units thereof, as will be apparent from the following description.

Referring to the accompanying drawings, Figure 1 is a front view of a pneumatic motor embodying my invention. Fig. 2 is a longitudinal section through one of the units thereof on the line 22, Fig. 1. Fig. 3 is a transverse section through two of the units, in the plane of the line 3-3, Fig. 2.

Similar reference characters refer to similar parts in the different figures.

My improved pneumatic motor comprises a series of motor bellows 1, in the present instance five in number, each having its movable leaf 2 connected, by a link 3, with a common crank shaft fl:- The stationary or base leaf 5 of each bellows is increased in thickness over the usual construction, and intermediate its ends is provided with a transverse air channel 6, having a passage 7 opening upon the outer face 8 of said base leaf, which presents a plane extended surface for the sliding movement of a valve 9. The latter has a recess 10 on its under side, adapted to communicate, in all positions of the valve, with the passage 7; the said recess, during a portion of the valve movement, is disposed so as to cover an air passage 11, extending through the base leaf 5 and connecting the interior of the bellows 1 with the outer face 8 of said base leaf.

Each sliding valve 9 has an operative connection with the link 3 which operates the movable leaf of the motor bellows with which said valve is associated; in the present mstance, a member 12, preferably of wire, is firmly embedded in the upper end of each valve, and its extending portion is bent in the form of an eyelet 13, providing a horizontal pivot for a block 14. A valve rod 15, connected pivotally at one end to the link 3, has its other end screw threaded, and passing loosely through a substantially vertical aperture in the block 14, in con tact with each side of said block, retaining members 16, preferably consisting of threaded leather washers or nuts, are disposed for ad]ustment on said rod, to provide a means for varying the vertical position of the valve 9.

The rotation of the crank shaft 4 effects the reciprocation of the valves 9, as will be clearly understood. To provide a means for guiding each valve in such movement, the member 12 extends inwardly of the recess 10, coincident with the longitudinal axis thereof and terminating short of the lower end of said recess. Said inward extension passes through a stationary eyelet 17 projecting outwardly from the face 8 of the base leaf, and preferably carrying a packing 18 of felt or the like. The downward movement of a valve brings its recess 10 into a position to bridge the passages 7 and 11, thereby establishing communication between the interior of the motor bellows and the transverse air channel 6, as shown in Fig. 2. In this position of the valve, the air tension or pressure within the motor bellows corresponds to the tension in the air channel 6. As the valve is moved upwardly, the passage 11 is uncovered, thus effecting the communi cation of the interior of the motor bellows with the atmosphere.

In the assemblage of the several units above described, loose spacing washers 19, formed preferably of laminated blotting paper or other compressible material, are interposed between the adjacent sides of the base leaves 5, the same having apertures 20 providing for the inter-communication of the several air channels 6, whereby a continuous air channel through the several base leaves 5 is formed. Apair of tie rods 21, passing through all of the base leaves and. their interposed compressible washers 19, are provided with end nuts 22 which bind theassenibled units together; spring washers 23 between said nuts and the outer sides of each end leajt' serve to compensate for any shrinkage and to allow for any swelling or expansion. of the parts, and in addition maintain tight the joints constituted by the interposed washers 19.

The continuous air channel passing through the several base leaves 5 is con nected at one end of the assembled structure with a pipe 94 leading to a bellows, or other means, not shown, by which air may be exhausted from said channel.

The guiding means for the reciprocating valves 9, embodied in the eyelets 17 and the downward extensions of the members 12, provides a greatly simplified and superior construction over those now in general use, requiring a minimum number of relatively moving parts and thereby eliminating con siderable friction. In addition, the direct connection of the valve rods 15 to the members 1:2 of the valves, provides a construction in which the power for moving the valves is applied nearly in line with the plane of the seats 8 on which the valves slide, thereby decreasing the liability of the valves to permit the leakage of air, by reason of any endwise tipping motion.

I claim,

1. In a pneumatic motor, an assemblage of separable units, each comprising a motor Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

bellows having a stationary leaf and a movable leaf, the stationary leaves having alined air channels, compressible spacing means interposed between adjacent stationary leaves and being apertured to correspond to said air channels, and means extending through each stationary leait above and below said air channels and securing all of said units together, said means having yieldable stops at their ends to permit limited lateral movement of said units thereon,

2. In a pneumatic motor, a valve-seat, a valve slidable thereon, and carrying a guide member in alinement with the path of its movement, and a way for said guide member comprising a metal eyelet secured to said seat.

3. In a pneumatic motor, a slidable valve providing a recess in opposition to its: seat, and a member extending through one wall of said recess, and ailording, on the outside thereof, a driving connection for said valve,

the portion of said member within said recess affording a means for guiding the valve in its movement.

4. In a pneumatic motor, a slidable valve, a member carried thereby for connection at one end to an actuating device, and stationary means within the limits of movement of said valve for cooperation with the other end of said member to guide said valve upon its seat.

Dated this eighteenth day of November,

THEODORE P. BROWVN, "Witnesses Pmqnnorn Corrnnnnaon, NELLTE 'THALEN'.

Washington, D. C. 

